Not Applicable.
The present invention relates generally to an antenna feed and more particularly to an antenna feed for dual band satellite communications.
Broadband satellite networks compete with terrestrial and wireless technologies in offering Internet access and backbone transport telecommunications services. There are a number of advantages and some disadvantages of broadband satellite networks versus fiber, Digital Subscriber Loop (DSL), cable modems and Local Multipoint Distribution Service (LMDS) offerings. In general, the advantages of satellite systems over these alternatives are ubiquitous coverage, simplicity, bandwidth on demand, uniformity, asymmetry, low cost global coverage and rapid deployment for global services. The determination of which service to offer a given subscriber is determined by which service is most cost effective to meet the user needs. The broadband satellite cost advantage increases as the density of the population decreases and as the deployment of broadband services increases over a larger area.
The total growth of the VSAT (very small aperture terminal) market is projected to be more than 30% per year over the coming five-year period. Industry analysts predict that the traditional VSAT business sector will achieve 18.2% annual growth over the next five years while broadband VSAT applications for consumers are projected to achieve more than 130% annual growth over the same period. It is also expected that by the year 2003 more than 2.5 million U.S. consumers will have installed broadband direct satellite Internet access terminals based on Ku/Ka-band systems. It is further expected that the global market for residential (consumer) satellite terminals will increase from $2.35 billion in 2000 (principally Direct Broadcast Satellite (DBS) television) to approximately $8.2 billion in 2005 (integrated Internet, voice and television).
Existing art in the area of interactive video and Internet satellite communications (SATCOM) terminals has typically utilized bulky expensive waveguide-based feed components and multiple antenna feeds in order to meet the multi-band, multiple polarization requirements of such terminals.
In view of the above, it would be desirable to provide a mass-producible, low-cost, dual frequency band antenna feed for interactive video and Internet satellite communications terminals that will transmit in a single vertical or horizontal linear polarization (selectable at installation) at commercial Ka-band while simultaneously receiving both vertical and horizontal polarizations at commercial Ku-band.
An antenna feed that transmits in a single vertical or horizontal linear polarization at commercial Ka-band while simultaneously receiving both vertical and horizontal polarizations at commercial Ku-band is presented. The antenna feed includes a metal feed horn, an integrated corrugated ring filter, an outer conductor disposed coaxially about the feed horn, a hollow inner conductor disposed coaxially within the feed horn and a polyrod disposed within the hollow inner conductor. The antenna feed further includes a printed circuit board (PCB) having receive channel radio frequency (RF) probes, hybrid combiners and low-noise block (LNB) circuitry. The PCB is surrounded by a housing which is attached to the feed horn.